This invention relates to tape cartridges of the floating roller type.
One general class of tape cartridge includes a tape whose ends are wound onto two tape rolls, and which is driven by a drive belt that bears against the two rolls of tape to turn them. In order to produce tension in the tape, which is necessary for reliable operation, it is necessary to drive the takeup roll very slightly faster than the supply roll. One type of drive belt cartridge utilizes friction elements along the path of the drive belt, to apply drag to the belt so that the belt portion bearing against the takeup roll is under greater tension than the other side which bears against the supply roll. The greater belt tension at the takeup roll causes elongation of the belt and therefore causes the belt to move slightly faster so that it tends to drive the takeup roll slightly faster. U.S. Pat. No. 3,692,255 by Von Behren describes a cartridge of this type.
Another type of drive belt cartridge utilizes a floating roller about which the drive belt extends, with the belt being pressed against the tape rolls by the floating roller. U.S. Pat. No. 3,907,230, and French Pat. Nos. 2,212,981 and 2,220,841, describe a floating roller cartridge of this type. In order to drive the takeup roll at a very slightly greater speed than the supply roll, these floating roller cartridges utilize a thick and easily compressible belt, such as one constructed of rubber or a rubber-like plastic. The floating roller tends to press against the belt portion which contacts the takeup and supply rolls, and the force of the roller compresses the belt in thickness to that it elongates and moves slightly faster at the surface of the takeup roll than at the surface of the supply roll.
A cartridge of the type illustrated in the above U.S. and French patents is currently being marketed for use in data recording. This cartridge has a belt which is approximately 50 mils (thousandths of an inch) thick and constructed of a rubbery material. Although this type of floating roller cartridge is of relatively simple construction and operates reliably under certain conditions, it has the disadvantage that the highly elastic belt cannot rapidly accelerate and decelerate the tape, and therefore is not satisfactory for intermittent data recording operations where very rapid acceleration and deceleration of the type is necessary. A tape cartridge of simple construction, which operated reliably and was capable of rapid accelerations to full speed, would be of great value especially in intermittent data recording applications.